Bas A. Schoonderwoerd

Immediate Reinitiation of Atrial Fibrillation After Electrical Cardioversion Predicts Subsequent Pharmacologic and Electrical Conversion to Sinus Rhythm on Amiodarone

Ninety-one percent of patients with atrial fibrillation (AF) resisting electrical cardioversion because of immediate reinitiation of AF after the shock maintain long-term sinus rhythm with amiodarone and repeat cardioversion. Thus, immediate reinitiation of AF is an important sign that should guide further treatment in patients with electrical cardioversion-resistant AF.

Atrial Ultrastructural Changes During Experimental Atrial Tachycardia Depend on High Ventricular Rate

Introduction: Atrial structural and electrophysiologic changes occur during atrial tachycardia. The role of high ventricular rate in these processes remains to be established.

Long-term outcome of the atrioventricular node ablation and pacemaker implantation for symptomatic refractory atrial fibrillation

AIMS To investigate long-term outcome and to determine predictors of development of heart failure (HF) in patients with atrioventricular (AV) node ablation and permanent right ventricular pacing because of symptomatic refractory atrial fibrillation (AF). BACKGROUND Atrioventricular node ablation and subsequent permanent pacing is a well-established therapy for patients with AF. Long-term right ventricular pacing may induce HF. METHODS AND RESULTS In 121 (45 with previous HF) patients with drug refractory AF, AV node ablation and implantation of a pacemaker was performed. At baseline and after a mean follow-up of 4.3 +/- 3.3 years, New York Heart Association (NYHA) functional class for HF and left ventricular (LV) and atrial diameters were assessed. During and at the end of follow-up, hospitalizations for HF, mortality, and quality of life were assessed using the SF-36 and an AVN-specific questionnaire. No significant changes in NYHA functional class (87 vs. 77% in NYHA I/II at baseline vs. end of follow-up) and LV end diastolic diameter (51 +/- 7 vs. 52 +/- 8 mm) were observed. Left ventricular end systolic diameter decreased (from 37 +/- 9 to 34 +/- 7 mm, P = 0.03) and fractional shortening improved (from 28 +/- 10 to 34 +/- 9, P = 0.02) in all patients and in patients with previous HF, but not in patients without previous HF. Hospitalizations for HF occurred in 24 patients (20%), predominantly those with previous HF. All-cause mortality occurred in 31 (26%) patients. At the end of follow-up, quality of life was comparable with the control group. CONCLUSION Long-term outcome of AV node ablation and permanent pacing is good. Atrioventricular node ablation remains a treatment option for AF.

Long-Term Outcome After Catheter Ablation for Left Posterior Fascicular Ventricular Tachycardia Without Development of Left Posterior Fascicular Block

Long‐Term Outcome After Substrate‐Based Ablation of LPF VT During SR. Background: Catheter ablation of left posterior fascicular (LPF) ventricular tachycardia (VT) is commonly performed during tachycardia. This study reports on the long‐term outcome of patients undergoing ablation of LPF VT targeting the earliest retrograde activation within the posterior Purkinje fiber network during sinus rhythm (SR).

The influence of varying energy settings on efficacy and safety of endoscopic pulmonary vein isolation

BACKGROUND The optimal energy setting for endoscopic pulmonary vein (PV) isolation (PVI) has not yet been determined. OBJECTIVE To assess the influence of varying energy settings on the efficacy and safety of endoscopic PVI. METHODS In the current prospective study, 30 patients with paroxysmal atrial fibrillation were consented for PVI using the endoscopic ablation system. Ablation was performed by using 5.5 and 7.0 W (group A), 7.0 and 8.5 W (group B), and 8.5 and 10.0 W (group C) along the posterior and anterior portion of each PV, respectively. Intraluminal esophageal temperature was measured via a temperature probe with a cutoff of 38.5°C. Endoscopy was performed 2 days postablation. RESULTS After the completion of the initial circular lesion set, acute PVI was achieved in 25 of the 36 (69%) PVs in group A, in 29 of the 40 (73%) PVs in group B, and in 36 of the 40 (90%) PVs in group C, respectively. The rate of acute PVI was significantly higher in group C than in group A (P = .025) and group B (P = .045); there was no difference when comparing group A and group B (P = .77). Esophageal thermal lesions were detected in 0 of the 10 patients in group A, in 1 of the 10 (10%) patients in group B, and in 1 of the 10 (10%) patients in group C. Mean procedure and fluoroscopy times were 219 ±42 and 30 ± 10, 239 ± 61 and 38 ± 14, and 207 ± 31 and 28 ± 8 minutes for group A, B, and C, respectively. CONCLUSIONS The use of higher energy settings increases the efficacy of acute endoscopic ablation system-based PVI without comprising safety. Further investigation is mandatory before final conclusions can be drawn.

Asymptomatic brain lesions following laserballoon-based pulmonary vein isolation.

AIMS Laserballoon-based pulmonary vein isolation (PVI) for the treatment of atrial fibrillation (AF) has proven safe and effective. Silent brain lesions after AF ablation detected on magnetic resonance imaging (MRI) have been described for several technologies, but its incidence following laserballoon PVI is unknown. The current study sought to assess the incidence of new asymptomatic brain lesions in patients undergoing laserballoon-based PVI. METHODS AND RESULTS Patients referred for PVI underwent pre- and post-procedural MRI of the brain. A total of 86 patients were enroled into the study (laserballoon group: 44 patients, 15 female, age 63 ± 9 years, left atrial (LA) diameter 43 ± 5 mm; cryoballoon group: 20 patients, 6 female, age 61 ± 9 years, LA diameter 41 ± 4 mm; and irrigated radiofrequency (RF) group: 22 patients, 11 female, age 64 ± 8 years, LA diameter 43 ± 6 mm). There was no statistically significant difference between the groups with regard to new asymptomatic brain lesions detected on post-procedural MRI: 5 of 44 (11.4%) patients in the laserballoon group, 1 of 20 (5.0%) patients in the cryoballoon group, and 4 of 22 (18.2%) patients in the irrigated RF group, respectively. In the laserballoon group, one additional patient with a new cerebral lesion experienced transient diplopia. In a multivariate regression model the only risk factor for asymptomatic new lesions was the CHA2DS2VASc score. CONCLUSION Following laserballoon-based PVI, new asymptomatic brain lesions were detected in 11.4% of patients. A higher CHA2DS2VASc score, but not the ablation technology utilized, was the only associated risk factor.

Atrial natriuretic peptides during experimental atrial tachycardia: Role of developing tachycardiomyopathy

Introduction: Atrial tachycardia and chronic heart failure (CHF) are associated with elevated levels of atrial natriuretic peptide (ANP) and its amino terminal part NT‐ANP. Chronic high atrial rates may cause CHF due to a rapid ventricular response. The aim of this study was to establish the contribution of elevated atrial rate and of high ventricular rate, resulting in CHF, on ANP and NT‐ANP levels during chronic atrial tachycardia.

Rapid pacing results in changes in atrial but not in ventricular refractoriness

SCHOONDERWOERD, B.A., et al.: Rapid Pacing Results in Changes in Atrial But Not in Ventricular Refractoriness. It is well known that atrial tachycardia causes atrial electrical remodeling, characterized by shortening of atrial effective refractory periods (AERPs) and loss of physiological adaptation of AERP to rate. However, the nature and time course of changes in ventricular effective refractory periods (VERP) caused by rapid rates are to be established. After being instrumented with epicardial electrodes on both atria and both ventricles nine goats were subjected to 1 week of rapid AV pacing with a rate of 240 beats/min and an AV delay of 100 ms. Pacing was only interrupted for measurement of left and right AERPs and VERPs at three basic cycle lengths (BCL) of 400 ms, 300 ms, and 200 ms during sinus rhythm in the conscious animal. Left and right AERPs decreased at all BCLs, reaching minimum values after 3 days (right AERP at BCL of 400 ms, 96 ± 16 ms after 3 days vs 144 ± 16 ms at baseline, P < 0.05). In contrast, both left and right VERPs did not change at any BCL. This study demonstrates a difference between the atria and ventricles with respect to tachycardia induced changes in refractoriness.

Genetics of Atrial Fibrillation and Standstill

Atrial fibrillation (AF) is the most common arrhythmia and is associated with an unfavorable prognosis. Monogenetic forms of AF, however, represent a rare AF subtype. Although the identified mutations in affected family members have large effects, they do not seem to play a major role in more common AF present in the majority of the patients. The majority of patients have AF in association with concomitant (cardiovascular) conditions. In the last few years increasing data have been reported supporting the notion that there is a genetic component to more common AF. Recently, GWAS of the common AF phenotype have been successful in identifying three genetic loci associated with AF.

Familial Atrial Fibrillation and Standstill

Atrial fibrillation (AF), the most common arrhythmia, is associated with an unfavorable prognosis.1,2 The majority of patients have AF in association with underlying (cardiac) diseases.3 In 15–30% of the patients, however, a known etiology is absent.4,5 This condition is called lone AF. Some of these patients have a positive family history for AF and may have a genetic cause or predisposition.6 Atrial fibrillation as an inherited disease was first reported in 1943.7 Darbar et al.8 observed that familial AF is more common than previously recognized. Of the 914 patients with AF, 36% had lone AF. A positive family history for AF was present in 15% of these lone AF patients (5% of all AF patients).8,9